Vine mealybug spreading but management efforts pay

It’s still spreading to new vineyards and new areas throughout California, but a cooperative industry effort is keeping vine mealybug (VMB) from becoming a full-blown crisis.

“It continues to move into new vineyards, but PCAs and growers are learning how to manage it,” says Kent Daane, UC Cooperative Extension specialist. “The experienced PCAs deal with it fairly well. The only issue is that there is still too much reliance on organophosphates, and that’s what we’re trying to get away from.”

That problem is two-fold, according to Daane.

“Organophosphates are under scrutiny, so we don’t want to over-utilize them and raise even more red flags for the EPA’s phase-out programs. Additionally, we don’t want to create resistance problems.”

Although OPs are one of the quickest, easiest ways to control vine mealybug, there are other alternatives that are being researched and tried.

“We want to conserve an OP for use only once in a season,” Daane says. “There are several materials and tank-mixes we can use, and others on the horizon that look promising.”

Biocontrol measures such as parasitism and mating disruption are also encouraging. “We’ve had good results in Napa combining ant control with parasitoids,” Daane says. “We’re just now finishing up mating disruption trials with a synthetic hormone that has given us about a 40 percent reduction compared to the control.”

Although these measures might not be the “silver bullet” for VMB control, they are promising, according to Daane. “I think they will probably have to be used in combination with some sort of insecticide program, at least at first.”